/Engine/Source/Runtime/Engine/Classes/Engine/GameInstance.h
Called to actually start the game when doing Play/Simulate In Editor
virtual [FGameInstancePIEResult](API\Runtime\Engine\Engine\FGameInstancePIEResult) StartPlayInEditorGameInstance ( [ULocalPlayer](API\Runtime\Engine\Engine\ULocalPlayer) * LocalPlayer, const [FGameInstancePIEParameters](API\Runtime\Engine\Engine\FGameInstancePIEParameters) & Params )